In most known clip-on type sunglasses, the eyewires in which the sunglass lenses are mounted, or the sunglass lenses themselves in the case of wireless glasses, are joined at their top edges by a bridge member in the form of a bar or strip of a resilient, flexible material. Typically, the bridge member extends above the lenses and is bowed slightly outwards away from the lenses for biasing the lenses toward one another. To mount clip-on sunglasses of this type on a pair of eyeglasses, the lenses are rotated away from one another, flexing the bridge member. Then, the lenses are positioned juxtaposed with the eyeglass lenses, and then released, whereupon clips that are provided on the outer edges of the sunglass lenses are brought into engagement with the eyeglass frame for securing the sunglasses to the eyeglasses. The sunglasses are held in place on the eyeglasses due to the resilience of the bridge member which urges the clips into engagement with the eyeglass frame.
Conventionally, clip-on type sunglasses include four such clips, two clips located along the outer edge of the left sunglass lens and two clips located along the outer edge of the right sunglass lens. To remove the sunglasses, the wearer merely grasps the sunglass lenses at their top and bottom edges and rotates the lenses outwardly away from each other, which action moves the clips out of engagement with the eyeglass frame.
Although this type of clip-on mount provides for easy mounting and removal of the sunglasses, a downside of this mounting arrangement is that the clips on one or both sides can become disengaged inadvertently, releasing the sunglasses whenever an outwardly directed force is applied to one or both of the sunglass lenses, which can be a common occurrence if the wearer is participating in sports or other activities.
Moreover, this type of clip-on mount requires four clips for securing the sunglasses to the eyeglasses. Many sunglasses have lenses that are made of a light-weight plastic so that the weight of the pair of sunglasses is determined primarily by the frame and the clips. As such, the clips represent a significant portion of the weight of the sunglasses. Because clip-on type sunglasses add weight to the eyeglasses on which they are mounted, it is desirable to minimize the weight of the clip-on type sunglasses.
A further consideration is that most eyeglass wearers select the eyeglass frames that best complement their face. Eyeglasses that are currently very popular have a single bridge frame, with the bridge located at a height that is below the upper edge of the lenses. However, the bridge of most known clip-on sunglasses extends above the lenses. Consequently, when mounted on eyeglasses having a single bridge frame, such clip-on sunglasses give the eyeglasses the appearance of a double bar frame.
For the reasons stated above, and for other reasons stated below which will become apparent to those skilled in the art upon reading and understanding the present specification; there is a need in the art for clip-on type sunglasses which better conform to the shape of the eyeglasses with which they are used and which are characterized by a more secure mounting arrangement that substantially prevents the release of the sunglasses from the eyeglasses on which they are mounted unless such release is intentional. Moreover, there is a need for clip-on type sunglasses that are of a reduced weight.
Another style of eyeglasses have a double bridge (or double bar) frame. In addition to the bridge which is at a height below the upper edge of the lenses there is a second bridge (upper bridge) which generally connects the top portions of the eyeglass lenses. This second bridge protrudes from the top of the frame, making it difficult for a user to obtain clip-on sunglasses for these styles of eyeglasses. Clip-on type sunglasses have not been previously manufactured for double bridge style frames. Thus there is a need in the art for clip-on type sunglasses which can be used on a variety of double bridge eyeglass frames and which can provide a secure mounting arrangement. An embodiment of the present invention is described which has a bridge mounting which fits on the lower bridge of a double bridge eyeglass frame and is mounted independently of the upper bridge.